Coal pillar safety and surface deformation characteristics of wide strip pillar mining in deep mine

摘要

The wide strip pillar mining of Tangkou coal mine in Eastern China is the engineering background in the paper. Coal pillar safety and surface deformation characteristics of wide strip pillar mining in deep mine are studied by using in situ measurement, three-dimensional similar material simulation test, and theoretical analysis. Results show that in deep mine, the plastic zone's width of coal pillar becomes larger obviously and the vertical stress of coal pillar presents a saddle-shaped distribution. The lateral deformation of coal pillar mainly concentrates on the area 9.5 m from the edge of coal pillar, which is discontinuous, stepped, and mutational. In addition, if only one working face with strip pillar mining is mined, the influence extent caused by coal mining is weaker and the surface subsidence and curvature are smaller. If multiple working faces with strip pillar mining are mined, the surface subsidence is obvious, the subsidence factor is 0.22, the subsidence basin is larger but gentler and uniform, and the surface deformation is continuous and long term. On the basis of the characteristics of wide strip pillar mining in deep mine, the safety of wide coal pillar in deep mine is checked.